The present invention relates in a general manner to a device enabling one to close a frame and which has a lid which can be locked on the frame a key and a lock connected with the lid.
More precisely, the invention relates to a closing device with selective locking for closing a frame, which has a roughly flat lid selectively applied to the frame, a lock connected with the lid, and a key which has a socket and an arm one end of which carries the socket, the lid having an opening for access to the lock for the key, the lock having a latch which cooperates with a catch of the frame, and the key selectively assuming, with respect to the opening, a locking position, which the key can assume and leave freely, and in which the latch is trapped by the catch, and an unlocking position for which the key is trapped in the opening and for which the latch is disengaged from the catch.
A device of this type is known in the prior art and is described in the patent document EP 0 383 374.
However, while this known device relates specifically to a vertical advertising frame, closed,by a lightweight lid, the present invention refers to different applications and particularly to an application in which the lid is a cast iron cover closing, for example, a refuse hole provided in a roadway.
Two problems arise in the type of applications envisaged by the invention, namely, on one hand, difficulties in handling of the lid, which result directly from the high weight and possibly from the horizontal arrangement of the lid, and on the other hand, the need to prevent acts of vandalism and particularly to provide against unauthorized opening of the lid.
The aim of the invention is precisely to propose a device which can solve these problems.
For this purpose, the device of the invention, otherwise according to the generic definition of it given in the preamble above, is essentially characterized by the fact that the arm and the socket of the key are roughly perpendicular to one another, and by the fact that the arm is roughly perpendicular to the lid in the unlocking position of the key.
Thanks to this arrangement, the lid can be raised by the key while being held by the whole lateral surface of the socket and not simply by two stubs as is the case according to the specification of the earlier patent document mentioned, this solution being unsuitable for cast iron pieces because of their weight and their manufacturing tolerances.
Moreover, inasmuch as the socket is roughly parallel to the plane of the lid, the locking and unlocking mechanism is not directly visible and remains inaccessible to standard tools.
Under these conditions, it is, for example, possible to make it such that the opening gives access to a cavity of the lid into which a hole opens, and such that the opening has the shape of an xe2x80x9cLxe2x80x9d of which one limb, perpendicular to the hole, allows the key to pass from one of its positions, locking and unlocking, to the other when the socket is inserted in the hole, and prohibits movement of the arm parallel to the hole when the arm is roughly perpendicular to the lid while the socket is inserted in the hole.
The cavity advantageously has a first wall in the form of an inclined plane and which ensures the guiding of the socket in the cavity.
In order to make handling of the lid by means of the key even more easy, this key preferably has a handle connected with the arm, roughly parallel to the socket and arranged opposite it.
The aforementioned hole can be formed in a second wall, orthogonal to the first wall, with it possible for a shaft bearing the latch then to be arranged in the hole.
The aforementioned socket can have an internal axial rib capable of cooperating with an axial groove arranged on the shaft bearing the latch.
Furthermore, the socket of the key preferably has, on its opening part, two external opposite stubs capable of cooperating with guiding ribs at the bottom of the aforementioned cavity and of passing through the aforementioned hole whose edge has notches whose form corresponds to said stubs.
The shaft bearing the latch is, for example, mounted so as to turn on a lug parallel to the aforementioned wall containing the hole and has a flat part in order to connect in rotation the shaft and the latch which has the form of angle iron.
Preferably, the latch is elastically held by a limb of the angle iron on the aforementioned lug and between this lug and the aforementioned wall with the hole by means of a spring and washers.
The other limb of the angle iron forming the latch is, for example, capable of cooperating with a notch forming a catch arranged in a longitudinal member inside the frame.
The limb of the angle iron held on the lug advantageously has a hole with a flat part cooperating with the aforementioned flat part on the shaft for rotating the latch.